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DW-Manual-Sigma-280 Magnum-001   FORCE 12  SIGMA-280Magnum Assembly Instructions   Page  7   of   32 

 

_____13) 

With the nuts still loose on the U-bolts, align the element with: 

 

_____a) 

The T-bars horizontal  

_____b) 

The rivets on the element are pointing downward 

_____c) 

The 10-24 feed point screws are in the correct orientation to connect to the balun / 
hairpin or the optional relay box, about a 45 degree angle.  

_____c1) 

Double check that the 10-24 feed point screws are tight (underneath the flat 
washers). 

_____c2) 

When the element mounts are attached to the boom, the feed point screws 
should point towards the center of the boom (towards the mast). 

 

_____d) 

The slots in the PVC insulators are in the air gap. 

 
_____14) 

Now the nuts to hold the element can be tightened.  It is only necessary to tighten them until 

 

 

the element does not rotate with hand pressure, then about a half-turn more.   

 

_____a) 

Double check that the split lock washers under the nuts are compressed. 

 
_____15) 

Locate the element truss line. There are two pieces per element (one for each side/half). 

_____a) 

If the eye-bolts are not already installed in the riser on each element mount, slide one 
in from each side so that there is a loop (the eye) on each side of the riser. 

 
_____16) 

Attach the center of each line to the element and run the free ends back to the center riser. 

_____a) 

Attach each end to one of the loops, leveling the element as the line is tightened.  

_____b) 

It is not necessary to bow the element upward (“gull wing” style).  

_____c) 

Secure the lines at the center riser/eye-bolt. 

 
_____17) 

Repeat the above procedure for the other element. 

 
 
 
 

II. 

BOOM ASSEMBLY.

 

 
_____1) 

Locate all the boom sections and match up the joints (each one is engraved). 

 
_____2) 

Insert the boom bolts from the top of the boom at the joints, install and tighten the nuts. 

 
_____3) 

Locate the boom truss and install it in the appropriate holes. It will be held to the mast using 
a single U-bolt and saddle. 

 
_____4) 

Attach the elements to the boom ends. 

 

_____a) 

The mounting bolts are run from the inside-out. 

 

_____b) 

Start with the back bolts (farthest inside the boom). 

_____c) 

Slide the bolt through the boom, then through the element mounting bracket 
and add the split lock washer and nut, but do not tighten fully yet 

_____d) 

After all the bolts are in and the nuts are started, tighten all the nuts. 

 
 
 
 

Содержание Sigma-280 Magnum

Страница 1: ...coax feed line goes to the driver This manual describes building each dipole element the attachment to the boom of both and how to tune the antenna Yagis for 80 75 meters are tuned much differently t...

Страница 2: ...reflector is set first without the driver in the circuit to the correct frequencies for phone and CW The driver is then set with the reflector active Once set the reflector is not re adjusted as it is...

Страница 3: ...tached to the element and to the center riser post on the element mount The element tubing segments are both bolted and riveted The bolted joints are on the larger tubing and the riveted joints are on...

Страница 4: ...tion has either an A or B on it and the sections taper as they go towards the tip Assembly requires only that the identifications are matched All the rivet holes are pre drilled and will align exactly...

Страница 5: ...crimped swaged end of the larger piece _____2b If the rivet holes do not align please check to be sure the section is oriented properly and that the correct side A or B is on the correct side It shou...

Страница 6: ...of the two 2 cover tubes These will be the drain holes They can be drilled later but now is a better time _____f Spread the turns on the coils for about one 1 turn per inch or about one tubing diamete...

Страница 7: ...f the eye bolts are not already installed in the riser on each element mount slide one in from each side so that there is a loop the eye on each side of the riser _____16 Attach the center of each lin...

Страница 8: ...saddle can then be removed from each coil _____4 While tuning tape the covers and end caps to the element to prevent them from sliding out of reach _____5 If not already done attach both elements to t...

Страница 9: ...3 750 for the JA window the reflector should be tuned lower to about 3 750 The F B in the window will be a bit less but the operating bandwidth will be much wider The VSWR curve for the antenna both e...

Страница 10: ...the driver feed point on the relay box _____a Set the initial spacing on the hairpin coil about between turns _____28 Energize the CW Phone relays for LOW PHONE _____29 Tune the coils on the driver fo...

Страница 11: ...the antenna is balanced with the coax and balun _____2 Carefully lower the antenna into the cradle Be sure to watch for the relay box control lines and the coax feed line _____3 Center the antenna fo...

Страница 12: ...not designed This warranty does not cover transportation installation punitive or other costs that may be incurred from warranty repair or installation Force 12 Inc must be notified and warranty repa...

Страница 13: ...DW Manual Sigma 280 Magnum 001 FORCE 12 SIGMA 280Magnum Assembly Instructions Page 13 of 32...

Страница 14: ...DW Manual Sigma 280 Magnum 001 FORCE 12 SIGMA 280Magnum Assembly Instructions Page 14 of 32...

Страница 15: ...DW Manual Sigma 280 Magnum 001 FORCE 12 SIGMA 280Magnum Assembly Instructions Page 15 of 32...

Страница 16: ...DW Manual Sigma 280 Magnum 001 FORCE 12 SIGMA 280Magnum Assembly Instructions Page 16 of 32...

Страница 17: ...DW Manual Sigma 280 Magnum 001 FORCE 12 SIGMA 280Magnum Assembly Instructions Page 17 of 32 Sigma 280 Magnum at WA5VGI...

Страница 18: ...280 Magnum 001 FORCE 12 SIGMA 280Magnum Assembly Instructions Page 18 of 32 End of coil secured with 20 bolt Note cap is already on at the center The tube and outer cap are already positioned on the...

Страница 19: ...ma 280 Magnum 001 FORCE 12 SIGMA 280Magnum Assembly Instructions Page 19 of 32 Coil cover tube and caps Note the through bolts on this mounting bracket were for a proto type only The actual go from th...

Страница 20: ...ERROR undefined OFFENDING COMMAND f STACK...

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